The purpose of this project is to analyze, at the gene level, a collection of germinal mutations produced by various chemicals in the course of experiments using biochemical specific locus test and other mutation assay systems. The genes to be analyzed enclode LDH-C, GPI-1, MOD-1, PEP-3, and LEN-1. Multiple independently induced and/or spontaneous variants for each of these genes will be analyzed by cDNA probes produced from the normal (wild-type) mRNA for aberrant gene structure, processing, and expression.